Lubricious coatings for medical devices

ABSTRACT

An ultraviolet curable lubricious coating including at least one lubricious polymer and at least one oxygen-insensitive crosslinkable polymer, methods of making and using the same, and articles coated therewith.

FIELD OF THE INVENTION

This invention relates generally to the field of synthetic polymericcoating compositions for polymeric and metal substrates, to methods ofmaking and using the same, and to articles coated therewith.

BACKGROUND OF THE INVENTION

Water soluble, biocompatible compounds that impart lubricity to thesurface of otherwise non-lubricious materials are desirable for use onmedical devices which are inserted or implanted into the body. Suchmedical devices may include catheters that are utilized to deliver astunt, stent-graft, graft or vena cava filter, balloon catheters, otherexpandable medical devices and so forth. The industry has turned tohydrophilic lubricious coatings in order to overcome problems withcommonly used hydrophobic coatings such as silicone, glycerin or oliveoil.

Hydrophobic coatings have been known to bead up and run off when exposedto an aqueous environment, lose initial lubricity rapidly, and lackabrasion resistance. Residual amounts of silicone have also been knownto cause tissue reaction and irritation in patients. The loss oflubricity can lead to discomfort during insertion into a patient, anddamage to blood vessels and tissues due to frictional forces duringinsertion or removal of the device.

Hydrophilic coatings can be difficult to retain on the surface of amedical device when exposed to an aqueous environment such as that ofbodily fluids. One particular class of hydrophilic coatings which hasbecome popular for use are “hydrogels” which swell in an aqueousenvironment, and are capable of manifesting lubricity while in a “wet”or hydrated state. When hydrated, these substances have low frictionalforces in humoral fluids including saliva, digestive fluids and blood,as well as in saline solution and water. Such substances includepolyethylene oxides, optionally linked to the substrate surface byurethane or ureido linkages or interpolymerized with poly(meth)acrylatepolymers or copolymers; copolymers of maleic anhydride; (meth)acrylamide polymers and copolymers; (meth)acrylic acid copolymers;polyurethanes; poly(vinyl pyrrolidone) and blends or interpolymers withpolyurethanes; polysaccharides; and mixtures thereof.

Hydrogels alone, however, may still migrate from surfaces to which theyare applied when exposed to an aqueous environment. One way in which toobtain improved surface retention has been through the use of polymericnetworks in which one material is crosslinkable, or through the use ofinterpenetrating networks in which more than one material iscrosslinkable.

The crosslinkable materials are typically cured through the addition ofultraviolet (UV) radiation. UV curable systems typically function by oneof two mechanisms including a free radical mechanism or a cationicmechanism. One example of a class of materials which cure via a freeradical mechanism are the acrylate functional crosslinkers. Theseacrylates are sensitive to oxygen in that they can form stable radicalsin its presence, and thus require an inert gas purge.

Cationic cure mechanisms typically involve the use of a sulfonium oriodonium salt which decomposes when exposed to actinic UV radiationforming strong acids. This type of crosslinkable material is sensitiveto the presence of a basic species and to humidity.

There remains a need in the art for an improved crosslinkable materialuseful in forming lubricious coatings which is not sensitive to thepresence of oxygen or moisture.

SUMMARY OF THE INVENTION

In its broadest sense, the present invention relates to a lubriciouscoating wherein at least one component is an oxygen insensitivecrosslinkable material, and at least one second component is present toprovide lubricity. The lubricious coating may be employed on the surfaceof medical devices or components thereof.

The second component may be any lubricious polymeric material includinglubricious hydrophilic polymers, lubricious hydrophobic polymers or amixture thereof. Crosslinkable materials may also be employed.

In one aspect, the crosslinkable material is employed to form apolymeric network with a lubricious uncrosslinked hydrogel.

In another aspect, the oxygen insensitive crosslinkable component may beemployed in combination with at least one second crosslinkablecomponent, the result being a “semi-interpenetrating polymer network”.

In one embodiment, the crosslinkable polymer is a polyvinyl alcoholmodified with styrylpyridinium groups having the following generalchemical structure:

wherein m and n are positive numbers and X is an anion.

One advantage to using the styrylpyridinium modified PVA is that thestrylpyrdinium group itself is a chromophore or light absorbing groupthat initiates crosslinking, and therefore requires no photoinitiator,unlike conventional UV curable materials.

In one embodiment, the styrylpyridinium modified polyvinyl alcohol (PVA)is employed to form a polymer network with a polyethylene oxidehydrogel.

In another embodiment, the styrylpryidinium modified PVA is employed toform a polymer network with a polyurethane or a blend of polyurethanes.

The lubricious coatings may be employed on any polymeric or metallicsurface to provide lubricity to such surface. The lubricious coatingsfind particular utility on medical devices and components thereof suchas catheter shafts, guidewires, guidewire lumens, dilatation balloons,and so forth. The lubricious coatings may be employed on both inner andouter surfaces of such medical devices and components thereof.

The surface of the medical device may first be plasma treated such aswith helium or argon, for example, to improve the adherence of thecoating to the substrate.

The present invention further relates to a process for applying thelubricious coatings to the medical devices or components thereof. Suchmethod includes the steps of applying the coating to the device orcomponent thereof, and polymerizing the crosslinkable material(s) on thesurface of the device by administering UV radiation to the coatedsurface of the device. Application of the coating may be accomplishedout of solvent by spraying, brushing, painting, or so forth. Usessolvents include, but are not limited to, water, lower alcohols such asisopropanol, methanol and so forth. Extrusion, coextrusion, and otherapplication techniques may also be employed. Such techniques do notrequire the use of solvents.

If the lubricious polymer is also a crosslinkable material, aphotoinitiator may also be advantageously added to the coating mixtureif the cure is by the addition of radiation such as ultravioletradiation.

In another aspect, the present invention includes a drug delivery systemwherein the coating is secured to a device insertable into a livingbody, wherein the coating includes the oxygen-insensitive crosslinkablematerial, an uncrosslinked hydrogel, and a therapeutic drug, Thetherapeutic drug may be entrapped in the coating or can be leachablefrom the coating upon hydration of the coating.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a graph showing the force required to cycle a latex pad acrossa hydrated catheter according to the present invention as compared tothe force required for a prior art catheter.

DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENTS

While this invention may be embodied in many different forms, there aredescribed in detail herein specific embodiments of the invention. Thisdescription is an exemplification of the principles of the invention andis not intended to limit the invention to the particular embodimentsillustrated.

The lubricious coatings include at least one oxygen-insensitivecrosslinkable polymer and at least one lubricious polymer.

It has been found advantageous to employ an oxygen-insensitivecrosslinkable polymer having styrylpryidinium groups. Thestyrylpyridinium groups may be added to the backbone of a polymer chainby a condensation reaction, for example. In one embodiment, thestyrylpyridinium groups are added via a condensation reaction to thebackbone of a polymer chain having adjacent hydroxyl groups, thusforming an acetal linkage.

A more specific example of a useful oxygen-insensitive crosslinkablepolymer is one in which the styrylpyridinium groups were added to apolyvinyl alcohol (PVA) by a condensation reaction which formed anacetal linkage. The compound has the following general structure:

wherein m and n are positive numbers, and X is an anion.

X may be sulfate (SO₃ ⁻), carbonate (CO₂ ⁻), a halide ion such as Cl⁻,Br⁻, hydrogensulfate (HSO₃ ⁻), an alkylsulfate such as CH₃SO₃ ⁻,phosphate ion, p-toluene sulfonate ion, naphthalene sulfonate, methylsulfate ion, ethyl sulfate ion, phosphite, tetrafluoroborate,hexafluorophosphate, chloride-zinc chloride, trifluoroacetate, oxalate,alkylsulfonate having 1 to 8 carbon atom, sulfonates such astrifluoromethane sulfonate, arylsulfonate having 6 to 24 carbon atomsand 2-hydroxy-4-methoxybenzopbenone-5-sulfonate, and so forth.

The styrylpyridinium functional group cures via a cycloaddition reactionand the reaction therefore proceeds by neither a conventional freeradical process nor a cationic process, although it is believed to beradical in nature. Furthermore, the styrylpyrdinium group itself is achromophore or light-absorbing group that initiates crosslinking, andtherefore requires no photoinitiator, unlike conventional UV curablematerials. Peak absorption occurs at about 360 nm, absorption which isideally suited for Hg vapor lamps which are often used in industrialsettings to induce crosslinking.

Polyvinyl alcohol substituted with styrylpyridinium groups is watersoluble and requires no additional solvent, an additional benefit whenemploying the compound in a lubricious coating.

Other photosensitive groups which may be employed in theoxygen-insensitive crosslinkable polymers of the present inventioninclude, for example, styrylquinolinium groups and styrylbenzothiazoliumgroups. PVA polymers modified with such groups are described, forexample, in U.S. Pat. No. 5,021,505 which is incorporated by referenceherein in its entirety.

Other polymeric materials to which the styrylpyridinium groups may beadded include, for example, polyvinylpyrrolidones or polyacrylic acids,for example.

Upon addition of UV energy to the styrylpyridinium modified PVA, acrosslinking reaction takes place between the styrylpyridinium groupsand is believed to proceed according to the following mechanism:

This reaction proceeds via a 2+2 cycloaddition rather than by aconventional free radical or cationic mechanism. Thus, the reaction isnot sensitive to oxygen as is typical with free radical mechanisms aswith the acrylates for example, nor is it sensitive to bases or moistureas is typical with a cationic mechanism. Styrylpyridinium groups areknown to orient as shown during film formation such as duringcoating/drying processes. Because these groups orient in such a manner,one styrylpyridinium group does not need to diffuse through the coatingmedium to find another styrylpyridinium group to react with. Therefore,these groups are ready for reaction even prior to addition of UV energy.The cure rate is rapid and can take as little as 30 seconds or less andapp ears to be insensitive to temperature, curing rapidly attemperatures as low as −80° C., The rapid cure rate is beneficial overcommonly employed free radical polymers because they are diffusioncontrolled and cure rates tend to be slower.

These crosslinked structures are believed to trap other, more mobilelubricious polymeric materials within the crosslinked structure, thusimmobilizing the lubricious material such that it does not migrate asreadily from the surface to which the lubricious coating is applied.

The lubricious polymeric material may be hydrophobic, hydrophilic or amixture thereof and may also itself be a crosslinkable material. Withnoncrosslinkable hydrophobic or hydrophilic materials, theoxygen-insensitive crosslinkable compound may form polymeric networkssuch as those described in commonly assigned U.S. Pat. No. 5,693,034which is incorporated by reference herein in its entirety. In the lattercase wherein the lubricious polymeric material is also crosslinkable, aninterpenetrating network or IPN may be formed with theoxygen-insensitive crosslinkable polymer.

Examples of useful hydrophilic polymers include, but are not limited to,poly(acrylic acid), poly(methacrylic acid), polyurethanes, polyethyleneoxide (PEO), poly(N-isopolyacrylamide), or polymers ofhydroxyl-substituted lower alkyl acrylates, methacrylates, acrylamide,methacrylamide, lower allylacrylamides and methacrylamides,hydroxyl-substituted lower alkyl vinyl ethers, sodium vinylsulfonate,sodium styrenesulfonate, 2-acrylamido-2-methylpropanesulfonic acid,N-vinylpyrrole, N-vinyl-2-pyrrolidone, 2-vinyloxazoline,2-vinyl4,4′-dialkyloxazolin-5-one, 2- and 4-inylpruidine, vinylicallyunsaturated carboxylic acids having a total of 3 to 5 carbon atoms,amino-lower alkyl (where the term ‘amino” also includes quaternaryammonium), mono-lower alkylamino-lower alkyl and di-loweralkylamino-lower alkyl acrylates and methacrylates, allyl alcohol andthe like. Such polymers are known to swell in the presence of water andbecome slippery, and are often referred to in the industry as“hydrogels.” These polymers thus typically exhibit greater lubricitywhen wet. Lubricious hydrogels of this type are described in commonlyassigned U.S. Pat. No. 5,693,034 incorporated by reference herein in itsentirety.

In one embodiment, polyethylene oxide is employed in combination withthe oxygen-insensitive crosslinkable material.

In another embodiment, a polyurethane or a blend of polyurethanes isemployed in combination with the oxygen-insensitive crosslinkablematerial. Examples of polyurethanes which may be employed include, butare not limited to, TECOGEL® 500, TECOGEL® 2000, both of which areavailable from Thermedics, Inc. TECOGEL® polyurethanes are aliphaticpolyether polyurethanes which can absorb anywhere from about 5 times(TG-500) to about 20 times (TG-2000) their weight in water. Used incombination with a crosslinkable material according to the presentinvention, results in a semi-interpenetrating polymer network(semi-IPN). The crosslinkable material suitably crosslinks with itself,but not with the polyurethane(s).

In yet another embodiment, the polyurethanes of the type describedabove, are blended with polylurethanes which do not absorb as muchwater, and thus do not swell as much. Polyurethanes exhibiting waterabsorption anywhere from 0% up to about 2000% as described above, areavailable while the TECOGEL® polyurethanes are in the range of 500% to2000% based on their own weight. Using such blending, the amount oflubricity, or how much frictional forces are reduced, can be controlled.

Lubricious hydrophobic materials may also be employed in the presentinvention. The use of hydrophobic lubricious materials may require thatsome compatibility exist between the lubricious material and theoxygen-insensitive crosslinkable polymer in order to achieve asatisfactory amount of mixing. Examples of useful hydrophobic polymersinclude, but are not limited to, silicones, glycerine or olive oil, forexample. Lower molecular weight hydrophobic materials may be more easilyentrapped within the crosslinkable structure of the oxygen-insensitivecrosslinkable polymer.

In another aspect, the lubricious polymer may also be crosslinkable. Acombination of crosslinkable polymers can advantageously form what isknown in the art as a interpenetrating network or IPN if a secondmaterial which itself is crosslinkable is employed. IPNs areadvantageously employed to obtain satisfactory intermingling of twootherwise different materials such as one which is hydrophobic, and onewhich is hydrophilic. It is also believed that such structures can beemployed to obtain better retention on polymeric and metallic surfacespossibly through covalent bonding.

In the latter case, if a second crosslinkable material is also employed,a photoinitiator may be optionally added if the curing mechanism of thesecondary crosslinkable material is achieved through the addition of UVenergy, Unlike many UV curable systems, the stryrylpryidinium modifiedpolymers of the present invention require no additional photoinitiatorbecause styrylpyridinium groups are themselves chromophores which absorbin the UV range.

Other materials not described herein could advantageously be employedaccording to the present invention. The above lists are not exhaustiveand are intended for illustrative purposes only. There are an endlessvariety of polymeric materials which may be incorporated into thepolymer network or IPN according to the present invention.

Other materials such as antioxidants, fluorescing agents, plasticizers,UV stabilizers, and so forth may also be employed in the mixture. Suchmaterials are known to those of ordinary skill in the art.

The lubricious coatings according to the present invention find utilityon a variety of surfaces including polymeric, metallic, wood and soforth. These coatings are particularly useful on medical devices andtheir components including, for example, catheter shafts, guidewires,dilatation balloons, and so forth.

Some surfaces may first require a primer treatment prior to applicationof the lubricious coating. For example, polyolefin surfaces such aspolyethylene or polypropylene may require a glow discharge plasmatreatment. Other polymeric substrates, such as polyimides containingdiaromatic ketones and polyethylene terephthalate, have also been foundto be suitable substrates even when not plasma treated. Polyurethanesand nylons may be primed with a vinyl functional isocyanate. Metals,such as stainless steel and gold, may be first treated with a primersuch as a vinyl or acrylate functional silane for best adhesion. One ofordinary skill in the art is aware of such surface treatments.

The coating find utility on both inner and outer surfaces. Thelubricious coatings may, for example, facilitate delivery of a medicaldevice through a patient's vasculature. Application of the lubriciouscoating to the inner surface of an inner lumen in a catheter shaft mayreduce wire movement function during the use of a guidewire, forexample.

There are numerous other applications for such lubricious hydrogels asare known to those of ordinary skill in the art.

The coatings may be applied to both inner and outer surfaces by dipping,spraying, brushing, coextruding, and so forth.

The coatings may be applied to the desired surface by first mixing thelubricious polymer and the oxygen-insensitive crosslinkable material ina solvent or cosolvent mixture. Useful solvents include, for example,lower alcohols such as isopropyl alcohol, water, and so forth. Thesolvent may be selected based on the solubility of the crosslinkablematerial and the lubricious polymer. One of ordinary skill in the art isknowledgeable of such solvent selection.

Once the desired surface has been coated, the crosslinkable material maybe cured by application of UV light for a short period of time. The UVlight triggers the polymerization and crosslinking of the compound.Preferably, the mixture is cured using a high intensity ultravioletlamp. The precise amount of time needed to cure the surface is dependenton the source of energy, the relative amounts of constituents in thecomposition, the thickness of the coating desired, and other factors. Aninitial cure is typically quite rapid, however, and can take as littleas 30 seconds or less. However, it is possible that some curing maycontinue after the UV light has been removed.

Using the oxygen-insensitive crosslinkable polymer offers manyadvantages over currently other conventionally used crosslinkablepolymers. First, as noted above, no purge with an inert gas is requiredbecause it is insensitive to the presence of oxygen. A second advantageis that no photoinitiator is required to crosslink the polymer.

Third, when the oxygen-insensitive crosslinkable material is employed incombination with a noncrosslinkable hydrogel, the coating may be highlylubricous when wet. In the dry state, however, the coating is virtuallyindistinguishable from the substrate. This offers an advantage over somelubricious coatings that remain tacky even when in a dry state.

Fourth, the lubricious coating of the present invention can be appliedto a variety of different substrates with strong adherence due to thecrosslinking reaction. Thus, the polymer network or IPN, depending onthe lubricious polymer selected, provides a lubricous, as well as anadherent and durable coating. Vigorous rubbing and long-term hydrationdo not reduce the coating's lubricity, demonstrating the strong adhesionof the coating.

Fifth, as mentioned previously, the oxygen-insensitive crosslinkablematerial according to the present invention can be employed incombination with a noncrosslinkable material such as a noncrosslinkablehydrogel, for example polyethylene oxide or polyvinylpyrrolidone, toform a polymer network in which the hydrogel is virtually entrappedwithin the system. Entrapment prevents material from leaving the coatingand entering the body. This feature can be employed to entrap variouspolymers within the crosslinked structure including hydrophobicmaterials as well as hydrophilic materials.

Sixth, the polymer network of the present invention is useful as a drugdelivery system. By varying such parameters as the molecular weight ofthe lubricious polymer and the crosslink density of theoxygen-insensitive crosslinkable polymer, an additional constituent,such as a therapeutic drug, can be incorporated into the present polymernetwork. The drug may also be entrapped in the polymer network or IPNand leaches out of the coating when the coating is wet delivering thedrug to immediately adjacent areas of the body. The advantages ofincorporating a drug which is released from the coating on medicaldevices is apparent. Effects of thrombus formation, restenosis,infections, and even disease transmission could be minimized oreliminated through the use of the coating of this invention.

The following non-limiting examples further illustrate the presentinvention.

EXAMPLES Test Methods 1. Lubricity Test Method

Lubricity was measured using a device that cycles a latex pad along thelength of a catheter. The catheter was immersed in water. The latex padwas affixed to an armature to which an 80 g weight is applied. Thearmature was then further connected to a force gauge. The catheter wasthen cycled back and forth across the pad by a motor drive. Force wasmeasured as a function of the number of cycles. The lower the forcerequired, the greater the lubricity.

Example 1

A hydrophilic coating was prepared using LS 400 styrylpyridiniummodified polyvinyl alcohol (4.1% styrylpyridinium functional groups)available from Charkit Chemical Corp.

The coating formula used was the following:

10 parts polyethylene oxide (900,000 MW)1 part polyvinyl alcohol modified styrylpyridiniumdiluted with water to 2% solids and to 4% solids

Outer shafts formed from PEBAX® 7033, polyether-block-amide, and havinga 0.042″ diameter were first plasma treated with helium (He), spongecoated with the formula shown above, air dried at room temperature, andUV cured at 360 nm for 30 seconds on each side using a Hg vapor lamp.The coated shafts were then tested for lubricity and durability usingthe Lubricity and Durability Tester.

Comparative Example A

A mixture of, polyethylene oxide in a cosolvent blend of 3.75:1isopropyl alcohol (IPA) to water was applied to a balloon formed ofPEBAX® 7033 as described above. A small amount of neopentylglycoldiacrylate (NPG) crosslinker was also added to the mixture at a ratio of10:1 PEO to NPG. Azobis-isibutironitrile photoinitiator was also addedin a minimal amount effective to initiate NPG polymerization. Theformula was then diluted to 2% solids and to 4% solids with water. Thisis an industry standard.

Outer shafts formed from PEBAX® 7033, polyether-block-amide, were spongecoated with the formula shown above, air dried at room temperature, andUV cured for 30 seconds on each side. The coated shafts were then testedfor lubricity and durability using the Lubricity and Durability Tester.

The results of the above testing is shown in the following table.

TABLE 1 Lubricity Test, Force (g) Example 1 Comp A Example 1 Comp AStrokes @ 2% solids @ 2% solids @ 4% solids @ 4% solids 2.73 1 1.80 4.001.60 1.25 2.80 2 3.87 2.75 3 2.08 4.80 1.60 2.40 3.00 4 5.57 2.20 7 3.405.50 1.65 2.20 2.80 8 6.13 2.60 9 3.76 6.50 1.55 2.45 3.20 10 8.50 2.3015 4.48 11.17 1.40 2.60 21 5.88 12.70 1.85 2.80 25 6.68 13.50 1.90 2.853.60 30 13.87 2.80 35 8.12 15.03 2.00 2.95 41 9.24 17.76 2.10 3.20 5019.11 3.50 51 10.84 2.56 62 19.47 4.25 71 14.2 22.94 2.84 4.80 80 5.0081 16.24 2.95 89 16.52 2.92 90 2.60 2.60 6.45

FIG. 1 is a graph summarizing the data shown in Table 1. As can be seenfrom the graph, the frictional force required to cycle the latex padacross the catheter for is less for example 1 than for comparativeexample A, an industry standard. The frictional force is a measure oflubricity. The lower the force, the higher the lubricity.

The above disclosure is intended to be illustrative and not exhaustive.The description will suggest many variations and alternatives to thoseof ordinary skill in the art. All of these alternatives and variationsare intended to be included within the scope of the attached claims.Those familiar with the art may recognize other equivalents to thespecific embodiments described herein which equivalents are alsointended to be encompassed by the claims attached hereto.

1. An ultraviolet curable lubricious coating comprising: a) at least onelubricious polymer; and b) at least one polymer which is crosslinkableby an oxygen-insensitive non-cationic mechanism.
 2. The lubriciouscoating of claim 1 wherein said at least one lubricious polymer ishydrophobic, hydrophilic or a mixture thereof.
 3. (canceled)
 4. Thelubricious coating of claim 1 wherein said at least one lubriciouspolymer is a noncrosslinked hydrogel.
 5. The lubricious coating of claim1 wherein said at least one lubricious polymer is crosslinkable.
 6. Thelubricious coating of claim 5 wherein said lubricious polymer and saidat least one oxygen-insensitive crosslinkable polymer form aninterpenetrating network.
 7. The lubricious coating of claim 1 whereinsaid crosslinkable polymer comprises at least one styrylpyridiniumgroup.
 8. The lubricious coating of claim 1 wherein said crosslinkablepolymer has the following general structure:

where m and n are positive numbers and X is an anion.
 9. The lubriciouscoating of claim 1 wherein said lubricious polymer is a hydrophilicpolymer selected from the group consisting of poly(acrylic acid),poly(methacrylic acid), polyurethanes, polyethylene oxide,poly(N-isopolyacrylamide), or polymers of hydroxyl-substituted loweralkyl acrylates, methacrylates, acrylamide, methacrylamide, lowerallylacrylamides and methacrylamides, hydroxyl-substituted lower alkylvinyl ethers, sodium vinylsulfonate, sodium styrenesulfonate,2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrole,N-vinyl-2-pyrrolidone, 2-vinyloxazoline,2-vinyl4,4′-dialkyloxazolin-5-one, 2- and 4-inylpruidine, vinylicallyunsaturated carboxylic acids having a total of 3 to 5 carbon atoms,amino-lower alkyl (where the term ‘amino” also includes quaternaryammonium), mono-lower alkylamino-lower alkyl and di-loweralkylamino-lower alkyl acrylates and methacrylates, allyl alcohol, anycopolymers thereof, and mixtures thereof.
 10. The lubricious coating ofclaim 9 wherein said lubricious polymer is polyethylene oxide.
 11. Thelubricious coating of claim 9 wherein said lubricious polymer is apolyurethane or a blend of polyurethanes.
 12. A medical devicecomprising: a) a tubular member; b) a coating on said tubular member,said coating comprising at least one hydrophilic polymer and at leastone polymer which is crosslinkable by an oxygen-insensitive,non-cationic mechanism.
 13. The medical device of claim 12 wherein saidoxygen-insensitive crosslinkable polymer comprises styrylpyridiniumgroups.
 14. The medical device of claim 12 wherein saidoxygen-insensitive crosslinkable polymer has the following generalstructure:

where m and n are positive numbers and X is an anion.
 15. The medicaldevice of claim 12 wherein said at least one hydrophilic polymercomprises at least one member selected from the group consisting ofpoly(acrylic acid), poly(methacrylic acid), polyurethanes, polyethyleneoxide, poly(N-isopolyacrylamide), or polymers of hydroxyl-substitutedlower alkyl acrylates, methacrylates, acrylamide, methacrylamide, lowerallylacrylamides and methacrylamides, hydroxyl-substituted lower alkylvinyl ethers, sodium vinylsulfonate, sodium styrenesulfonate,2-acrylamido-2-methylpropanesulfonic acid, N-vinylpyrrole,N-vinyl-2-pyrrolidone, 2-vinyloxazoline,2-vinyl4,4′-dialkyloxazolin-5-one, 2- and 4-inylpruidine, vinylicallyunsaturated carboxylic acids having a total of 3 to 5 carbon atoms,amino-lower alkyl (where the term ‘amino” also includes quaternaryammonium), mono-lower alkylamino-lower alkyl and di-loweralkylamino-lower alkyl acrylates and methacrylates, allyl alcohol andmixtures thereof.
 16. The medical device of claim 15 wherein said atleast one hydrophilic polymer is polyethylene oxide.
 17. The medicaldevice of claim 15 wherein said at least one hydrophilic polymer is apolyurethane or a blend of polyurethanes.
 18. The medical device ofclaim 17 wherein said at least one hydrophilic polymer is an aliphaticpolyether polyurethane.
 19. The medical device of claim 18 wherein saidat least one aliphatic polyether polyurethane can absorb from about 500%to about 2000% water by weight.
 20. The medical device of claim 12wherein said tubular member has an inner surface and an outer surface,said hydrophilic coating is on said inner surface said outer surface ora combination thereof.
 21. (canceled)
 22. A dilatation balloon with acoating, said coating comprising at least one lubricious polymer and atleast one polymer which is crosslinkable by an oxygen-insensitivenon-cationic mechanism. 23-43. (canceled)